• Journal of Aerospace System Engineering
• /
• v.16 no.6
• /
• pp.90-98
• /
• 2022

The output of an infrared (IR) sensor mounted on an EO/IR payload is known to change during a mission period in an orbital environment. As it is required to calibrate the output of the IR sensor periodically to obtain high-quality images, an on-board black body system is mounted on the payload. All systems operating in the space environment require performance tests on ground to verify the target performance in the orbital environment. Therefore, it is also required to test the black body system to verify the performance of the surface temperature uniformity and the estimated representative temperature error within the target temperature range in the operating environment. In this study, calibration of the estimated representative temperature error and verification of the thermal performance of the black body system were conducted by performed a performance test in the thermal vacuum chamber applying deep space radiation cooling effect of an orbital environment.

• Journal of the Korea Society of Computer and Information
• /
• v.21 no.5
• /
• pp.127-133
• /
• 2016

In this paper, an intelligent dimming control system is designed and implemented with the human visual response function using CDS sensor, PIR sensor and temperature sensor, etc. The proposed system is designed to detect a moving object by PIR sensor and to control the LED dimming considering the human visual response. Also, the dimming of LED light can modulate on the app, and simultaneously control dimming in real-world environments with smart phone app. A high-temperature warning or a fire hazard information is transmitted to user's smart phone according to sensor values and Data graph are provided as part of data visualization. Connecting the hardware controller, the proposed intelligent smart dimming control system is expected to contribute to the power reduction interior LED, smart grid building and saving home combining with internet of things.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.17 no.9
• /
• pp.2191-2204
• /
• 1993

A sensor system has been developed to measure the posture(position and orientation) of mobile robots working in industrial environments. The proposed sensor system consists of a CCD camera, retro-reflective landmarks, a strobe unit and an image processing board. The proposed hardware system can be built in economic price compared to commercial vision systems. The system has the capability of measuring the posture of mobile robots within 60 msec when a 386 personal computer is used as the host computer. The experimental results demonstrated a remarkable performance of the proposed sensor system in the posture measurement of mobile robots - the average error in position is less than 3 mm and the average error in orientation is less than 1.5.

• International Journal of Aeronautical and Space Sciences
• /
• v.1 no.1
• /
• pp.70-80
• /
• 2000

The attitude knowledge error model is formulated for specifically KOMPSAT attitude determination system using the Lefferts/Markley/Shuster method, and the attitude determination(AD) error analysis is performed so as to investgate the on-board attitude determination capability of KOrea Multi-Purpose SATellite(KOMPSAT) using the covariance analysis method. Analysis results show there is almost no initial value effect on Attitude Determination (AD) error and the sensor noise effects on AD error are drastically decreased as is predicted because of the inherent characteristic of Kalman filter structure. However, it shows that the earth radiance effect of IR-sensor(earth sensor) and the bias effects of both IR-sensor and fine sun sensor are the dominant factors degrading AD error and gyro rate bias estimate error in AD system. Analysis results show that the attitude determination errors of roll, pitch and yaw axes are 0.056, 0.092 and 0.093 degrees, respectively. These numbers are smaller than the required values for the normal mission of KOMPSAT. Also, the selected on-orbit data of KOMPSAT is presented to demonstrate the designed AD system.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1992.10a
• /
• pp.344-348
• /
• 1992

This paper presents a new methodology for on-line tool breakage detection by sensor fusion concept of an acoustic-emission (AE) sensor. A built-in piezoelectric force sensor was used to measure cutting force instead of a tool dynamometer to preserve the machine tool dynamics. he sensor was inserted in the tool turret housing of an NC lathe. FEM analysis was carried out to locate the most sensitive position for the sensor. When a tool is broken, the explicit changes of signals' pattern take place. A burst-type AE signal increases abruptly. Followingly, a cutting force drops significantly. Therefore a burst of AE signal is used as a triggering signal to inspect the following cutting force. Significant drop of cutting force is utilized to detect tool breakage. The algorithm was implemented in a DSP board for in-process tool breakage detection. The proposed monitoring system was capable of a good applicable tool breakage detection.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.9 no.6
• /
• pp.112-118
• /
• 2001

In this study the leakage current measurement method based on a porous ceramic is applied to check the conductive substance caused by the ionized particles. By using engine and chassis dynamometer and an experiment vehicle, in which the hydrocarbon sensor (HC sensor) was exposed to the exhaust gas to create the electrical signal, the HC sensor in the exhaust line checked the conductive ions in emission gas. Generally the output electrical signal of HC sensor is followed with amount of hydrocarbon in the experiments in cold start and operation. By combining the electrical signal, a measure of conductivity of exhaust gas with hydrocarbon can be provided by OBD (On Board Diagnosis) II and EMS (Engine Management System).

• Bulletin of the Korean Chemical Society
• /
• v.31 no.11
• /
• pp.3084-3092
• /
• 2010

This paper describes the development of an automated, hand-held sensor for the fast assessment of seafood freshness. The sensor developed here combined: an array-based chemical sensor, composed of incrementally different conducting polymer elements deposited on a small chip; a highly sensitive, custom-made electronics for the detection of very small signal changes; precise temperature control of the sensor chamber; and an on-board microcontroller for data collection, storage, automation, and analysis. The instrument was used to successfully test seafood samples with different degree of freshness and spoilage. A linear relationship between microbiological count and e-Nose signal for three different fish fillet was developed. Once the linear relationship is included into the hand-held unit software, the e-Nose signal can be used for assessment of seafood freshness without performing the microbiological count technique.

• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.5
• /
• pp.420-427
• /
• 2010

This paper describes a localization method based on Monte Carlo Localization approach for a mobile robot. The method uses range data which are measured from ultrasound transmitting beacons whose locations are given a priori. The ultrasound receiver on-board a robot detects the range from the beacons. The method requires several beacons, theoretically over three. The method proposes a sensor model for the range sensing based on statistical analysis of the sensor output. The experiment uses commercialized beacons and detector which are used for trilateration localization. The performance of the proposed method is verified through real implementation. Especially, it is shown that the performance of the localization degrades as the sensor update rate decreases compared with the MCL algorithm update rate. Though the method requires exact location of the beacons, it doesn't require geometrical map information of the environment. Also, it is applicable to estimation of the location of both the beacons and robot simultaneously.

• Journal of Sensor Science and Technology
• /
• v.24 no.5
• /
• pp.299-305
• /
• 2015

Since the natural disasters such as floods, droughts, heat wave and cold wave are increasing, the need for risk management is necessary to minimize the damage with utilizing IT technology. Also, the monitoring services of disaster response type have been developed and applied. Recently, the open source hardware based on the signal of the sensor, or the monitoring studies have been carried. In this paper, by analyzing a low-cost open source hardware platform such as Beagle board, we examine the utilization of the hardware-based module for sensor monitoring.

• Journal of the Korean Society of Industry Convergence
• /
• v.12 no.4
• /
• pp.215-219
• /
• 2009

A packaging technology based on flip-chip bonding and Pb-free solder for silicon pressure sensors on printed circuit board (PCB) is presented. First, the bump formation process was conducted by Pb-free solder. Ag-Sn-Cu solder and the pressed-screen printing method were used to fabricate solder bumps. The fabricated solder bumps had $189-223{\mu}m$ width, $120-160{\mu}m$ thickness, and 5.4-6.9 standard deviation. Also, shear tests was conducted to measure the bump shear strength by a Dage 2400 PC shear tester; the average shear strength was 74 g at 0.125 mm/s of test speed and $5{\mu}m$ shear height. Then, silicon pressure sensor packaging was implemented using the Pb-free solder and bump formation process. The characteristics of the pressure sensor were analogous to the results obtained when the pressure sensor dice are assembled and packaged using the standard wire-bonding technique.